Maine State Police name person of interest in the disappearance of Florida firefighter Jerry Perdomo

(CBS/AP) AUGUSTA, Maine -- Maine State Police, who suspect foul play in the disappearance of Florida firefighter Jerry Perdomo, have now named Daniel Porter a person of interest in the case.

Perdomo, a 31-year-old Seminole County firefighter has been missing since Feb. 16. He disappeared shortly after he traveled in a rental car up the East Coast to visit a friend. ABC News reports Porter, 24, and his girlfriend, Cheyanne Nowak, are believed to be the last people who say Perdomo.

State Public Safety Department spokesman Stephen McCausland said investigators have spent two days gathering evidence at a house in the Waldo County town of Jackson that's owned by Porter's father. It is thought to be the last place Perdomo was seen.

"The work being done at the lab will hopefully give us some of the answers to our questions," Christopher Coleman of the Maine state police said. "At this point we remain hopeful, but as days go on, we have to be realistic. We do suspect foul play was involved."

A friend of Perdomo's told ABC affiliate WFTV that Perdomo went to Bangor to sell prescription pills and that he'd mentioned someone named "Daniel" previously. Perdomo's family told the station that he has never used or sold drugs. His wife, Tonya Perdomo, is pleading for her husband's safe return.

"The connection between Perdomo, Porter and Nowak, we're still trying to piece together," said McCausland. Perdomo made frequent trips to Maine, he said. A woman claiming to be Perdomo's girlfriend has come forward to police but McCausland did not have her name.

Investigators also have moved three vehicles involved in the case to the crime lab. They include a rental car Perdomo had been operating, which was found in the parking lot of the Bangor Wal-Mart; a car that had been owned by Porter and was left behind at an Oakland dealership and a new car bought by Porter and Nowak.

Police also confirmed they searched a trash container at the Hannaford supermarket in Bangor, near Wal-Mart.

Meanwhile, Perdomo's firefighter colleagues made a weekend trip to Maine to join his family in searching for him.